---

	FORUM ON BEER, HOMEBREWING, AND RELATED ISSUES
		Digest Janitor: janitor@hbd.org
		Many thanks to the Observer & Eccentric Newspapers of 
		Livonia, Michigan for sponsoring the Homebrew Digest.
				URL: http://www.oeonline.com


Contents:
  Liquid yeast in Canada ("Paddock Wood Brewing Supplies")
  Misguided Post Hogs ("plotek")
  dry lager yeast (Warandle1)
  High SG beer phase 1 ("Richard")
  Need help with DWC malt analysis ("Dean Fikar")
  Temperature Control (Joe Kish)
  RE: all-grain brewing video (LaBorde, Ronald)
  plastic conical fermentors (Doniese)
  Grain (David Todd)
  RE:Yeast Bugs ("Chris Stehlik")
  Does anyone own a Brewer's Edge Controller II? (WayneM38)
  Cold break layering (Keith Busby)
  mbaa chapter 7 (smorgan)
  fusels and growth rate / detecting mutant yeast ("George de Piro")
  Rims mistake for gott cooler type mash tuns. (Joseph Gibbens)
  Commercial Pitching rates ("Bob Page")
  PART2 - Re: FAN/amino acids in yeast nutrient ("Stephen Alexander")
  PART1 - Re: FAN/amino acids in yeast nutrient ("Stephen Alexander")
  Brewmaster needed (Lou.Heavner)
  Pitching onto yeast cake (David Boyd)
  valley mill gap settings (patrick finerty)
  Wolfy Weighs In on PRates (Biergiek)
  yeast counts ("Alan Meeker")
  YPD for yeast starters ("Alan Meeker")
  Enamel over steel, and thanks (kevin m mueller)
  References (Dave Burley)
  Boiling Flame Source... Does It Matter? (Richard Foote)
  re: Fire VS steam for the decoction heat source (Charley Burns)
  DME for yeast starters (JDPils)


* Beer is our obsession and we're late for therapy!

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Date: Sat, 19 Feb 2000 14:28:53 -0600
From: "Paddock Wood Brewing Supplies" <orders at paddockwood.com>
Subject: Liquid yeast in Canada

Hi Rod,

I hope this is not classed as spam, but I saw your post about liquid yeast
in Canada and thought you should know that we supply Wyeast to homebrewers
across the country.  If we don't have what you are looking for, we can grab
some with any order we place with Wyeast. We tend to order from them every
6-8 weeks, so the product is fresh.

Steve Cavan  -- "Life is too short to drink bad beer"
______________________________________________
Paddock Wood Brewing Supplies, Saskatoon, SK
orders at paddockwood.com  www.paddockwood.com




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Date: Sun, 20 Feb 2000 08:20:18 +1100
From: "plotek" <plotek at optusnet.com.au>
Subject: Misguided Post Hogs

From
Henk van der Gaast
aka MudGuts


I have been reading this
newsletter for a few months.
As far as the other brewers that
i deal with, in Australia, we have
started to think that you guys are a bit
wankerish.

This site hogging and opinion airing
by a minority of the correspondants
suggests to me that a lot of you spend
a major time believing your talents rather
than actually knowing what you speak of.

When ive personally questioned some
of these fountains of knowledge, i get
fairly similar answers.  Mostly, huh?,
 what are you talking about? are
you joking? What does this email mean?

to the guys who espouse great gobbets
of knowledge beyond beer brewing
dont post until you know what you are
talking about. Theres a lot of brewers
 who are scientists and engineers
who also know what is being written
is worse than improbable - its often
utter shite.

Illogical mini experiments with no follow
up do not make a paper, nor
 a presentation.  It Just makes
a beacon called an email adress
that signals where the idiots live.

Nor does posting endless tracts
of regurgitated prose that is for the most
misinterpreted.

Please consider the other brewers
that read your tripe.  They start out trying to
make a beer that is "perfect" compared
to the trash thats available commercially.
Or Possibly- try to emulate some of
the super beers that are so expensive
that case drinking them would be
a lifestyle unto itself.

Having these endless issues that focus
on the minutiae of the irrelevant would
certainly lead them to repeat work
that means naught.

So as i read it,  Post pearls- dont be
swine

Henk
(MudGuts)
Australia





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Date: Sat, 19 Feb 2000 17:18:18 EST
From: Warandle1 at aol.com
Subject: dry lager yeast

Date: Fri, 18 Feb 2000 10:51:31 -0500
From: "Nathaniel P. Lansing" <delbrew at compuserve.com>
Subject: dry lager yeast?

I noticed it is often mentioned that, "there are no good dry lager yeasts,
none that have true lager characteristics."
 Does anyone know _what_characteristics are referenced in this *momily* ?

I have read (sorry Dr. Pivo for the literature reference) in homebrewing 
literature (Papazian) that lager yeasts (yeasts that are meant to and can 
ferment at lager temp--45-55 F) can not survive the drying process like an 
ale yeast can.  So a true lager yeast can only be found in *liquid* form.  My 
practical experience (Dr. Pivo should be proud) with  Morgan's Lager Dry 
Yeast shows that a dried lager yeast will not ferment at lager temps.  I 
pitched at room temp and after it really started to ferment at a high rate I 
moved it to a 45-50 F room.  Once cool, it stopped cold.  It seemed to have 
stop fermenting completely.  I moved back to room temp. and it took off again 
after warming up.  The liquid lager yeasts I use move quite well at 45-50 
degrees.

So this *momily* thing.  Is that when people assume something to be true but 
has not been proving to be true?  

Will Randle
Ashland, MO


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Date: Sat, 19 Feb 2000 16:04:05 -0800
From: "Richard" <seaotter at orland.net>
Subject: High SG beer phase 1

Ok, last night I pitched a starter of Red Star Pasteur Champagne Yeast into
the high SG beer. This AM I have about 1/2 inch of krausen and about 5
bubbles/min in the airlock (previously had none to speak of). So something
is going on. Further reports to follow.

Rich



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Date: Sat, 19 Feb 2000 21:38:58 -0600
From: "Dean Fikar" <dfikar at flash.net>
Subject: Need help with DWC malt analysis

I just bought a sack of DWC Munich and the lot analysis has me concerned:

Lot # 349139: DWC Munich

% Moisture: 3.70
Color: (Lovibond) 7.80
Turbidity: 10.0
Viscosity: 1.49
Alpha Amylase:
Diastic Power:
Extracts (FGAs): 79.9
Extracts (FG): 83.0
Extracts (CGAs): 79.5
Extracts (CG): 82.6
Extracts (F/C): 0.4
Proteins (Soluble): 4.78
Proteins (Total): 9.49
Proteins (S/T): 50.37

The last item, the S/T ratio, jumps out at me as indicating way overmodified
malt.  Should I be concerned?  I'm told by the Schreier rep that the more
typical lot would have an S/T ratio of 45-47% and that this batch is "on the
high side".  I've made some great beers with DWC malts in the past but I'm
wondering if this sack of Munich might lead to thin, insipid beer.  I've
used up to 90% Munich in my alts and bocks in the past.  I'd appreciate some
help from someone with more expertise in interpreting malt analyses than
I've got.

BTW, kudos to Schreier for making this info freely available on their web
site.

Thanks,
Dean Fikar
Fort Worth, TX









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Date: Sat, 20 Feb 1999 11:02:19 -0800
From: Joe Kish <JJKISH at worldnet.att.net>
Subject: Temperature Control

In HBD 3253, Terence Tegner mentioned a home made
temperature controller he built himself.
 I'm interested!!  How can we Start the Ball Rolling?
   We need Part Numbers, Sources, Companies, etc.
I doubt if the HBD can send diagrams to be read in
ACROBAT format, so maybe someone with a web page will
be nice enough to let us 'Borrow' his site!! :-)
    Joe Kish


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Date: Sun, 20 Feb 2000 16:04:29 -0600
From: rlabor at lsumc.edu (LaBorde, Ronald)
Subject: RE: all-grain brewing video

>From: "Lyga, Daniel M." <lygadm at pweh.com>

>	I was wondering if anyone knows of a source for an all-grain
>hombrewing video.

Yes, Brew Ha Ha has produced  an excellent ideosyncratic video.  If you call
or write, you can probably get one sent to you at a very reaonable price.
504-895-5745 4905 Magazine Street, New Orleans, LA 70115.

Ask for Mike or Gabe, and tell 'em Ron sent you.

Ron

Ronald La Borde - Metairie, Louisiana - rlabor at lsumc.edu
http://members.xoom.com/rlabor/



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Date: Sun, 20 Feb 2000 19:21:59 EST
From: Doniese at aol.com
Subject: plastic conical fermentors

Recently, several people have brought up plastic conical fermentors and where 
to find them.  A company called Hobby Beverage Equipment Company makes 5.5, 
6.5, and 12 gal plastic conicals with stands, thermometers, racking arm, 
bottom drain valve, etc.. I don't have a web address, but the literature that 
I got from a local Homebrew supply shop has a snail mail, phone, and an Email 
address for information.  Maybe this will help someone:  

Hobby Beverage Equipment Co.
Box 1387
Temecula, CA. 92593
909-676-2337
jthomas at iinet.com




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Date: Sun, 20 Feb 2000 19:54:27 -0500
From: David Todd <royalair at home.com>
Subject: Grain

Hi I was wondering how long grain can be stored I have some malted barly
that is about 1 year old and I have stored it in a frezer at 40 degrees
is it still good to use thanks Dave Todd



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Date: Sun, 20 Feb 2000 17:09:35 PST
From: "Chris Stehlik" <chrisfs59 at hotmail.com>
Subject: RE:Yeast Bugs 


>Consider
>the Burton Union system, how sterile is that? It still makes fine beer. I
>like to see a bacterialogic report from _that_ yeast.
>

Consider as well the way many belgian beers and especially lambics are 
brewed,
where 'unsanitary' conditions are not just tolerated but encouraged or
downright necessary.

Whenever I am faced with people who demand extreme cleanliness, I remind 
myself
that beer, good beer, had been brewed for hundreds of years before Pasteur 
and
germ theory ever came along. Somehow the monks in Chimay and Rochefort made 
it
without autoclaves, iodophor or even bleach. They did it without  sterile 
(or
not so sterile) Wyeast packs, and stored it in wooden(!) casks which every
knows is ideal for bacteria and yet, they made and continue to make great 
beer.
______________________________________________________
Get Your Private, Free Email at http://www.hotmail.com



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Date: Sun, 20 Feb 2000 22:29:48 EST
From: WayneM38 at aol.com
Subject: Does anyone own a Brewer's Edge Controller II?

Someone recently suggested a Brewer's Edge Controller II to control my HERMS 
RIMS brewery. (Thanks Jerry!)

I have been looking for an affordable/accurate temperature controller to 
control the heating coil return flow of Big Fun Brewing. A PID will not work 
well because of the variable temps of my bottom fired HLT. Many off the shelf 
controller units have too wide a differential to make them useful for 
brewing. While there seems to be a few good digital controller components 
(Thanks Mike!) , I don't have time to build a controller from components at 
this time. I'd rather be brewing.

Does anyone own a Brewer's Edge Controller II?

http://www.williamsbrewing.com/temperature.htm#Controller%20II

Please share your experience with this digital temperature controller.

E-mail would be great.

Thanks in advance.

Wayne


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Date: Sun, 20 Feb 2000 21:41:35 -0600
From: Keith Busby <kbusby at ou.edu>
Subject: Cold break layering

Shortly after pitching yeast in my last few batches, I have noticed what I
take to be a layer of cold break suspended a few inches down from the top
of the wort. I do not recall seeing this until recently. Could it have
anything to do with my use of oxygenation (this is the only recent change
to my techniques)? The final beer has not been affected in any way,
although lag time has been longer (as long as 12 hrs.) than I would have
expected from a wort that had been oxygenated (Oxynater) for two 30-second
bursts. Yesterday, I chilled the wort to about 70F before pitching.

Keith Busby


George Lynn Cross Research Professor
Center for Medieval and Renaissance Studies
University of Oklahoma
780 Van Vleet Oval, Room 202
Norman, OK 73019
Tel: (405) 325-5088. Fax: (405) 325-0103

Starting Fall 2000, Professor of French
University of Wisconsin-Madison


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Date: Mon, 21 Feb 2000 15:42:22 +1000
From: smorgan at expressdata.com.au
Subject: mbaa chapter 7


afternoon,

I got the majority of the mbaa downloads, except chapter 7 which is showing as
damaged.

Did anyone else pull these down as i would like to have a look.

To the southern highland guy, I know alot of rugby players in the southern
highlands. persist and i will send them around.
your rantings are tiring to say the least.

scotty




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Date: Mon, 21 Feb 2000 01:59:13 -0500
From: "George de Piro" <gdepiro at mindspring.com>
Subject: fusels and growth rate / detecting mutant yeast

Howdy all,

Steve A. writes, regarding the production of fusels:

"It's largely the growth RATE rather than the total
amount of growth that matters most.  Relates to the concentrations of
oxo-acids in the case of fusels, and to other flavor effects too."

Back to me:

Yes.  This is the major reason that a brewer will maximize the chance of
producing a "clean" tasting lager if the yeast are pitched into cold wort
rather than warm.  By pitching your yeast into a 70F wort and then chilling
it after fermentation starts you are allowing the rate of yeast growth to be
quite high.  The fusels thus produced may be in high enough quantities to
mar the beer's flavor.

Some brewers (including me) will pitch all of their beers about 5F below the
intended fermentation temperature and allow the heat of fermentation to
bring the wort to the desired temperature.  In this way, yeast growth is
slowed a bit and a "cleaner" tasting beer results.  This also acts as a sort
of QC tool:  I know that it should take the yeast a certain amount of time
to get the wort up to fermentation temperature.  If it is longer (or
shorter) I know that something is different, and that I should pay close to
attention to the batch (not that I don't pay close attention to all of my
batches, but I might start growing new yeast just in case I decide not to
harvest from the oddly behaving batch).

I believe that pitching temperature may be one of the major reasons that
many homebrews display excessive amounts of fusels, as well as some beers
made with yeasts that people believe need to be fermented at high
temperatures.  Many Belgian and Weizen yeasts ferment most completely (and
with very agreeable flavors) at temperatures higher than typical (70-75F).
These yeasts need not be pitched at that high temperature, though.

I typically pitch my Weizen at about 58-62 (it's tough for me to be terribly
accurate), and allow the heat of fermentation to bring it up to 70F.  This
results in a clean-tasting Weizen:  it is rich with the desirable phenols
and esters, but the fusels that so commonly give homebrewed Weizen a harsh
edge are at palatable levels.
- ----------------------------------
Steve A. writes, regarding plating out yeast to isolate pure cultures:

"Certain mutant, such as oxygen deficient mutations occur regularly at
high rates (0.5%!) and so avoiding these means choosing culturing
conditions that prefer normal growth - plating out won't help here."

Back to me:

There is a wonderful media called "Respiratory Mutant Deficient Agar"
(RMDA), available as pre-poured plates from the Brewing Science Institute in
Colorado (no affiliation, blah, blah...).  This miraculous substance allows
one to differentiate between normal and respiratory deficient mutants by
colony color.  Normal colonies are pink to red while mutants are white.
Simply select only reddish colonies!  How easy is that!  The real bonus:
the stuff isn't even too expensive!

It is critical to the survival of humanity that mutant yeast be detected and
destroyed with great efficiency.  If an organism with the ability to produce
psychoactive chemicals were to ever get loose, there would be no hope for
any of us...

Have fun!

George de Piro  (Nyack, NY)

C.H. Evans Brewing Company
at the Albany Pump Station
(518)447-9000
http://evansale.com (under construction)

Malted Barley Appreciation Society
Homebrew Club
http://hbd.org/mbas

George de Piro

C.H. Evans Brewing Company
at the Albany Pump Station
(518)447-9000
http://evansale.com (under construction)

Malted Barley Appreciation Society
Homebrew Club
http://hbd.org/mbas



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Date: Mon, 21 Feb 2000 02:02:04 -0600
From: Joseph Gibbens <jgibbens at umr.edu>
Subject: Rims mistake for gott cooler type mash tuns.

Hello,

Thanks for all the replies about conical fermenters and hot/cold break.

Just in case anyone is considering an upgrade to a RIMS and has a Gott 
type cooler mash tun...

NEVER build a false bottom supported by machine screw legs unless you put 
a SS or Copper plate under the legs.  I just managed to pull six 1/8in diam 
machine screws THROUGH the inner liner of a 10 gal cooler from pump 
suction.  

I'm going to go out on a limb and call it bed compaction, but there was 
never any flow rate problem.  

What are some ways to correct this situation?  common 
sense says says stir the mash and put the flow choke at a valve.  
Unfortunately, I'm an engineering student, so common sense (being in 
short supply) needs to be saved up for things like looking both ways 
BEFORE crossing the street... 

1. If I build a reinforced false bottom and get a decent recirculation 
rate, do I need to care about bed compaction?

2. Putting the flow choke at a control valve can be accomplished by 
taking something like a plastic graduated cylinder, piping the mash tun 
output into the top, and draining from the bottom.  That way, the 
pressure under the false bottom can't drop much under atmospheric 
pressure.  If compaction is a problem, will there be a problem with the 
grain compacting under its own weight only?

3. A stirrer would probably be a good addition reguardless.  What kind of 
flow do I need to create in the mash? (blade geometry?)  Also, is there 
an established optimal relationship between stirrer RPMs and mash thickness?


Joe



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Date: Mon, 21 Feb 2000 04:54:45 PST
From: "Bob Page" <icerigger at hotmail.com>
Subject: Commercial Pitching rates

The debate rages. Several points have been made on the assumption that 
commercial breweries pick their pitching rate for reasons of flavour etc.

Sorry, they pitch high for one reason only, money. They cannot afford a 12 
hour lag. If they can force through a batch of beer in 96 hours, a 3 hour 
lag vs. a hour lag results in a 10% productivity gain.

When you consider the hundreds of millions of dollars in revenue which are 
at stake, the shareholders and owners would crucify any brouwmeister who 
pitched low.

Bob's official $0.02
______________________________________________________
Get Your Private, Free Email at http://www.hotmail.com



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Date: Mon, 21 Feb 2000 08:04:49 -0500
From: "Stephen Alexander" <steve-alexander at worldnet.att.net>
Subject: PART2 - Re: FAN/amino acids in yeast nutrient


> 3) the concentrations of the above that can be expected in all grain
> worts, and

See M&BS table 14.5 for a general outline, or look in the HBD 2392 for
my post on amino acids and  multiply the mg/dL figures by 10 to
approximate ppm.

> 4) the situations in which supplements to the wort might be required?

Since normal yeast growth levels in normal wort nearly depletes the
GroupA and GroupB amino acids it is reasonable to assume that
additional growth and growth rate would benefit from replacement of
those depleted amino acids.

> In regard to the above questions, I have seen diammonium phosphate as
> a common ingredient in "yeast nutrients". Is this to prevent fusel
> alcohol production, or is this to enhance yeast growth, or are these
> issues not related?

It doesn't prevent fusel production in any way.  If the amino acid level is
high to begin with the yeast will ignore the ammonia and produce fusels
by the Ehrlich mechanism.  If the levels are (or eventually are) low, the
ammonia ions give the yeast the additional opportunity to produce
fusels by the synthetic mechanism.

The easy ways to reduce fusels are to switch yeasts or limit growth.
That isn't what you want to hear if you are trying to grow a big batch of a
chosen yeast really fast.

Another possibility is avoid amino acid synthesis and yet reduce the
oxo-acid
pool in the yeast cells.  Oxo-acids are the 'heads' of the amino acids,
while
the ammonia ions are the 'tails'.  Whenever yeast consume AAs they
immediately
separate the heads and tails even if they need to rebuild the very same
amino
acid they just tore apart.   It probably has to do with the regulation
mechanisms.
Anyway if you feed your yeast just one, or a few  amino acids it will use
the 'tails'
to make the others and to some smaller extent the 'heads' will be reused.
The
unused 'heads' or oxo-acids are just begging to be made into fusels or
aldehydes.
To reduce fusels for a given yeast and a given growth rate,  you *might* try
feeding
a mix of amino acids that precisely match the growth requirements of that
particular
yeast.  This is where that Chemostat Jim Liddel mentioned a few months back
will really come to good use.

> Protein hydrolysates and peptones are also typcially found in "yeast
> nutrients".  Apparently amino acid concentrations can be deficient at
> times.  I assume these are necessary under conditions in which amino
> acid concentrations are low (musts?).

Right, but I wouldn't be at all interested in finding these in beer.  They
are
not pure sources of amino acids and will likely carry over flavors from
their sources (such as beef muscle).

>I also have seen added thiamine
> in mixtures of "yeast nutrients" or "energizers" for homebrewers.  I
> assume this is an essential amino acid that con be deficient in worts
> (or perhaps only in musts).

No.  Water, oxygen, amino acids and sugars are the major nutriles by
volume, but the list of necessary yeast nutrients is long and in part
unknown. Thiamine is a vitamin for humans as well as yeast.  Many
vitamins are basically enzyme co-factors, chemicals that allow the
thousands of enzyme mediated pathways in a yeast cell to operate.
Some of the trace metal requirements, like zinc and manganese also
serve this purpose.  No vitamins - no growth.  Of course different brewers
strains have different vitamin reqs.  Some to be aware of are inositol,
pantothenic acid, biotin, thiamine, pyroxidine, nicotinic acid and
para-aminobenzoic acid.  Don't imagine that this is even close to a
complete list.  Yeast of course need various minerals and organic
chemicals for growth as cell constituents.  Consider the source of all
the sulfur atoms used throughout the yeast.

> I would like to better understand the driving force behind fusel
> alcohol production (which, of course, can be a flavor problem with
> beer) versus the limitations on yeast growth.

I can suggest some reading, but it will get deep fast. For general
discussions, 'The Yeasts' edited by Rose, Academic Press, and
Yeast Technology', Gerald Reed and Nagadawit... are both very
good. If you can handle a little differential equations, 'A Flavor Model
for Beer Fermentation' by Gee and Ramiriz [JIB vol100, p321-329]
and other papers by the same authors have a neat and concise
math model for fusels.

>I wish
> to better understand the issues behind making yeast versus making
> beer, so that I can control these at the APPROPRIATE TIME during the
> process.  Culturing yeast for brewing is not the same as brewing beer,
> and the two processes should not be confused.

Very insightful comment Fred - I completely agree. Culturing yeast is a
significantly different activity from fermenting beer.  I few years back I
tried
several methods of increasing yeast growth and was largely successful.
It's pretty trivial to double the resulting slurry volume for example.  The
problem is that the resulting yeast culture will stink of aldehydes, fusels,
VDKs, diacetyl, and in the case that you use UFAs or sterols the head
may be replaced by a greasy textured film.  Furthermore unless you take
some care the final treatment of these yeast - they are very prone to
autolysis unless kept growing.

Since I don't have access to a centrifuge that can quickly handle several
liters of yeast culture, the possible methods for separating the numerous
yeast from the nasty beer involved cold chilling/dropping, separation and
restarting on clean wort before pitching.  Perhaps you are clever enough
to find a way to separate out the nasty wort and still pitch the yeast under
exponential growth conditions without the several day delay involved in
chill-separating the good from the bad and ugly.


Incidentally I have read that British ale breweries will build well aerated
starters to about 10% of the batch volume, but then mix the first batch
since the 10% aerated starter volume detracts to significantly from the
flavor.  This goes against what appears to be a growing HB practice of
pitching a continuously aerated starter volume into 'production' HB.

fwiw,
 -S





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Date: Mon, 21 Feb 2000 08:08:47 -0500
From: "Stephen Alexander" <steve-alexander at worldnet.att.net>
Subject: PART1 - Re: FAN/amino acids in yeast nutrient

Fred L. Johnson writes ...

> Could someone provide a brief summary of
We'll battle the  8kB monster.

> 1) the requirement for free amino nitrogen by yeast for growth, (i.e.
> is free amino nitrogen "required" for growth or just to prevent fusel
> alcohol production?)

We (speaking for all living organisms) have an absolute need for
nitrogen in order to form protein, and also the nucleic acids for
DNA and RNA. Amino acids are the basic building blocks for proteins.
There are 20 common alpha-amino acids which can be snapped
together (takes a little energy)  end-to-end to form chains (peptides
and proteins).  Nitrogen also appears in a number of other important
biochemicals in yeast.

Most bacteria and fungi (and in all probability yeast) can reduce
nitrate to ammonia, or consume ammonia ions directly for use,
or can consume certain free amino acid as a source nitrogen. 
Several studies also show that yeast can use amino acids from
very small peptides (amino acids chains of short length).  Yeast
can use nitrogen from certain nucleotide base compounds. Larger
peptides and proteins cannot be utilized by yeast.


WORT:

Of course there is no typical wort, but we must start somewhere. 
Wort made from grain (unmalted) adjunct has much lower amino acid
content than wort made from all malt, so when making a wit with
50% unmalted wheat you should expect low FAN levels.  M&BS
describes an 11P wort made from 1.3%N(8.1%protein) low protein
malt as containing 728-862 ppm of Nitrogen (from all sources). 
While similar wort made from 1.8%N(11.25%protein) malt had
958-1154ppm N.  After fermentation the figures for the two worts
were 342-426ppm N and 541-736ppm N respectively.  In other
words the totoal nitrogen level of the worts was nearly proportional
to the malt nitrogen level and the fermentation process removed
40% to 50% of the total nitrogen.  Understand that these are
measures of all nitrogen in the wort and beers and the losses
include protein precipitation and yeast consumption. To
understand more we must look closer at the fractions.

The middle of the road 11P all-malt wort contains from 728-1154
ppm (see above) but only about 40% of that amount 200-400ppm
appears  as FAN and half or less of this remains after fermentation,
22-210ppm (various sources) of FAN.

GroupA amino acids(AA) are used early and quickly by yeast and
are typically completely absorbed during the first day of fermentation.
Glutamate, aspartate, asparagine, glutamine, serine, threonine, lysine
and arginine are the 8 aminos in this category.  This group includes
all of the acidic AAs, and the two hydroxyl containing AAs and 2 of 3
of the basic AAs.

GroupB AAs are absorbed gradually throughout fermentation and
include histidine, valine, methionine, leucine and isoleucine.  Includes
the other basic AA (histidine), the largest 3 of the 5 aliphatic AAs
and methionine, a sulfur containing AA.

GroupC aminos are consumed after an appreciable lag period
and include glycine, phenylalanine, tyrosine, tryptophan, alanine.
The two smaller aliphatics AA, and the 3 aromatic AAs.

GroupD - This one amino acid is treated peculiarly by yeast.  The
cyclic amino acid proline appears to be almost untouched by
fermentation and the FAN levels in finished beer are dominated
by the proline fraction.

This grouping which appears in several brewing texts leaves
cysteine, a sulfur containing AA  unclassified.  Cysteine does
appear prominently in yeast cytoplasm proteins, and it seems
likely that yeast consume cysteine from wort since low FAN
beers (e.g the 22ppm value one above) obtain virtually all of
there FAN as proline.

Very generally the GroupA and GroupB  AAs are very depleted
(<20% of the original values appear in beer as post-boil wort, and
often <10%). The GroupCs are much more variably removed,
sometimes leaving considerable glycine and alanine.

Wort also contains roughly 25ppm of ammonia of which about
half is consumed during fermentation.  The ammonia is
consumed in a pattern similar to the GroupC AAs.  The ammonia
consumed might be compared to about 75ppm of FAN.

YEAST:

Yeast have about 45-50% of their dry mass as protein, and
about 9% or 10% of their dry mass as nitrogen alone 
AAs account for about 80% of yeast nitrogen use and much of
the remaining nitrogen appears in yeasts astonishingly high
levels of  nucleic acids.  The high levels of nucleic acids
detract from yeasts food value.


> 2) the amino acid requirements by yeast for growth

An interesting question which requires one to know the
specific brewing yeast intimately.  Yeast can use the nitrogen
from one amino acid to build another, but not all amino acids
can be used to supply the nitrogen and it slows the growth
rate considerably.  It is well known that most brewing yeasts
cannot grow on Lysine alone for example.  Probably other
limitations along this line.

If you are looking for a cheap and easy 'out' then you can
add ammonia salts and get growth, but for optimal growth
rate you'd need to experiment.  Perhaps supply a fairly
complete mix of amino acids for optimal growth, and try
decreasing the less fully utilized ones (GroupD and GroupC).
Unless you are trying to achieve efficiencies of large commercial
operation, or are in it out of curiosity I think you'd be hard pressed
to beat wort or other complete AA mixtures as a growth medium.  

(see part 2)
 -S





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Date: Mon, 21 Feb 2000 08:09:55 -0600
From: Lou.Heavner at frco.com
Subject: Brewmaster needed

     I am seeking a brewmaster who would be interested in consulting part
     time.  Megabrewery experience is preferred.  It won't be necessary to
     relocate, but some travel is expected.  This is a US opportunity at
     this time, but could potentially lead to some international exposure.
     If you are interested, please contact me off-line at
     lou.heavner at frco.com.

     Cheers!

     Lou Heavner - Austin, TX


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Date: Mon, 21 Feb 2000 10:12:34 -0500
From: David Boyd <dave_boyd at mclean.sterling.com>
Subject: Pitching onto yeast cake

Greetings:
	The recent discussion on pitching rates has given rise to some
questions.   I normally try to plan ahead and make a starter but think
I still may be underpitching given some of the harsh overtones and high
finishing gravity's in my recent beers.  When I pulled my last beer out
of the primary I rinsed the yeast cake then left it covered with water.
My intent had been to brew in the next couple days.  Well time waits for
no brewer and it has now been a couple of weeks.   The yeast cake is still
covered in water, the airlock in place, and no sign of bacteria.  So my
question is can I safely put my next beer onto this yeast cake or should
I clean the carboy and forget it?

	
- -- 
David W. Boyd, Director                        Voice: (703) 506-0800, ext 7048
Network and Information Operations Dept.       Cell: (703) 577-5824
Sterling Software, Applied Systems Division    Fax: (703) 506-0154
1650 Tysons Blvd, Mclean, Va 22102-3915        E-Fax: (360) 838-1106
E-Mail: dave.boyd at sterling.com


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Date: Mon, 21 Feb 2000 10:22:29 -0500 (EST)
From: patrick finerty <zinc at zifi.psf.sickkids.on.ca>
Subject: valley mill gap settings

fellow brewers,

i just picked up a Valley Mill this past week. when i brew again, i'm
planning on doing a two stage crush. the gap settings on the mill are
not marked and i'm curious what *positions* (ie, third from the top,
etc.) on the mill people are using for this type of application. 

 -patrick in toronto
- -- 
       "There is only one aim in life and that is to live it."
 Karl Shapiro,(1959) from an essay on Henry Miller's Tropic of Cancer
	      finger pfinerty at nyx10.nyx.net for PGP key
		 http://abragam.med.utoronto.ca/~zinc


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Date: Mon, 21 Feb 2000 10:26:31 EST
From: Biergiek at aol.com
Subject: Wolfy Weighs In on PRates

>Date: Sat, 19 Feb 2000 10:09:50 -0500
>From: William Macher <macher at telerama.lm.com>
>Subject: Decotion heat source...does it matter?
>
>Hi All,
>
>Ok! I have a confession! My name is llib rehcam.

Ilib, whatever it is you are smokin', I want some.

Now, more stuff on pitching rates.  In Germany, one of their beer gods is 
this dude named Wolfgang Kunze.  Wolfy has written a brewing text book that 
is used to train brewers in Germany (an excellent book, BTW, and can be 
purchased on line from the Brewing Institute of Berlin, www.vlb-berlin.org).  
Here is what he has to say regarding pitching rates:

"As a rule, yeast is pitched into wort at a rate of 20 million cells/ml...) 
p. 325

Perhaps Pivo will comment since this is not an Amerikan megabrewery reference.

How is the average Joe homebrewer going to do this?  Some of us who use stir 
plates and have microscopes have been talkin'.  We have found that we can 
grow yeast in our starters at the rate of 100 million cells/ml of starter 
wort.  Using this factor we can estimate how large a starter is needed.  Lets 
get back to Wolfy's recommended pitching rate of 20 million cells/ml of 
chilled beer wort.  For a 5 gallon batch, the amount of yeast cells needed 
for pitching is:

Required Cell Count = (20E6 cells/ml)X(3785 ml/gal)X(5 gal) =  3.785E11 cells

Required Starter Volume = (3.785E11 cells) / [(100E6 c/ml)X(3785 ml/gal)] = 1 
gallon

If you don't have a stir plate I really don't know what kind of cell growth 
rates you can achieve, maybe 50E6 cells/ml?  If you don't want to buy a 
microscope but want to know your pitching rates I believe you can send a 
sample to the Brewing Sciences Institute who will do a cell count and 
viability count for $10 (www.brewingscience.com).

Kyle
Bakersfield, CA



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Date: Mon, 21 Feb 2000 10:51:34 -0500
From: "Alan Meeker" <ameeker at welchlink.welch.jhu.edu>
Subject: yeast counts

>From: "Parker, Mike" <mparker at CaseServices.com>
>You don't need a microscope for counts.  You pull a 1 ml sample
>sample from that, dilute x 10 again, and repeat for something like
>6 times total.  Then pour the last 10ml sample onto an agar petri
>dish, let it grow a day or so, then do an eyeball count.  If you
>diluted right you should get around 10-100 colonies.  Back-calculate
>by multiplying your count by 1x10E<#dilutions> to get your count/ml,
>then multiply by your starter size to get the total count.

Two problems with this method:

1) you have to wait for the colonies to grow up before you get the count

2) What you are counting is not number of yeast cells here but rather "cfu"s
= colony forming units. The progenitor any given colony you see on the plate
could be one single yeast cell or it could be a clump of cells.  This will
depend upon the particular yeast strain as well as the conditions of growth
and the stage at which you take your sample. When I did comparisons in the
past using the Bav. Wheat strain Wyeast 3068 I saw a big difference between
the actual cell numbers (as measured by hemacytometer counting on the
microscope) and the colony numbers. The 3068  showed a marked tendency to
form clumps of from 10 - 50 cells or so. Thus, if I had used colony number
to estimate my actual cell numbers here I would have been off by more than
10-fold.

One thing the colony method does yield however is information on viability
but this is also obtainable w/ vital dyes such as methylene blue.  But even
this info is less than ideal. It has been pointed out that viability
(ability to grow/reproduce), while a prerequisite for good performance, does
not give info on the yeast's /vitality/

 -Alan Meeker
 Lazy Eight Brewery
 Baltimore, MD




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Date: Mon, 21 Feb 2000 11:05:21 -0500
From: "Alan Meeker" <ameeker at welchlink.welch.jhu.edu>
Subject: YPD for yeast starters

Patrick in Toronto asks about using YPD for starters:

Patrick, I've been making most of my starters this way though I have
modified the procedure recently mostly out of paranoia. Since glucose makes
up nearly the entire carbohydrate source of YPD this will cause a general
suppression of the enzymes used for uptake and metabolism of the other
simple sugars - notably maltose. Also, such conditions may allow for
enrichment of mutants deficient in uptake of maltose and other wort sugars.
What this means is that when you eventually pitch into wort there may be an
increased lag time in order for the yeast to adjust to the new carbohydrate
spectrum (though perhaps not such a serious problem as there will be
significant amounts of glucose present in the wort and this will serve to
continue the suppression of the other pathways). Of more concern is the
possibility of a high proportion of maltose(-) mutants. Anyway, this may all
be moot but I've taken to making half of the sugar in my YPD maltose instead
of 100% glucose. ("YPDM?").

On the morning of my brew day I resuspend the yeast in about a quart of
sterile wort anyway so this may all be for naught but the way I see it it
can't hurt...

 -Alan Meeker
 Baltimore, MD




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Date: Mon, 21 Feb 2000 12:47:28 -0500 (EST)
From: kevin m mueller <kmmuellr at engin.umd.umich.edu>
Subject: Enamel over steel, and thanks

First of all I want to thank everyone for the great info on the Marga
Molino mill.  I did my first crush yesterday (need to motorize before my
arm falls off!), and I'm mashing as I write this.  Which leads me to
another question.

I decided to try mashing in my old enamel over steel brewpot.  It has a
small chip in it, and I was wondering if this will effect my flavor.  I
read some in the archives, and every article I read says there won't be
any off flavors if I use it to boil in.  I'm curious about mashing.

Thanks in advance, and feel free to use private e-mail.

Kevin

Remember, good health is the slowest possible rate at which one can die
- --Anonymous

                 



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Date: Mon, 21 Feb 2000 13:02:25 -0500
From: Dave Burley <Dave_Burley at compuserve.com>
Subject: References

Brewsters:

I am not a microbiologist nor do I pretend
to be one. And I sure don't want to get into
a battle of "my reference is bigger than
yours", but I thought  my comments based
on M&BS references ( never once
mentioning DeClerk) were in agreement
with and perhaps more succinct than
SteveA's on the origin of fusel alcohols.
I made the point that fusel alcohols have
two origins in the biochemistry of beer,
amino acids and carbohydrates and
don't see how that differs from SteveA's
comments. And I provided page 
references in a readily available text
for the reader to check out.

Kunze (1999) p 562-563  says : " Large
amounts of higher alcohols are mostly
found in beers with high (percentage-DRB)
alcohol content.........
These alcohols are produced by the
yeast by removing amino-groups from
amino acids present and replacing
them with the -OH group of the alcohol.
The amount of amino acid
(and type -DRB) plays a very important
role"


Keep on Brewin'


Dave Burley


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Date: Mon, 21 Feb 2000 13:16:33 -0500
From: Richard Foote <rfoote at mindspring.com>
Subject: Boiling Flame Source... Does It Matter?

Mr. llib rehcam writes about flame source influences on decoction mashing.
While I don't have any light to shed on that, I do have questions regarding
an associated matter--that of flame source influences on boiling.  I'm not
speaking about the type of boil, for example, but rather the flavor
outcomes in finished beer.  More to the point, I use a propane burner that
has a focused flame, not unlike that of a king-sized Bunsen burner.  I'm
not sure what brand it is, for reference sake, but it has a single orifice
through which the propane is forced with a 12 psi regulator up through a 2"
diameter by 4" long (approx.) section of pipe.  The sound is not unlike the
roar of a jet engine.  I seem to recall the BTU rating at 80,000.  

My question is this:  Has anyone conducted any 'spurments whereby beers
created using different types of burners were compared?  The more common
ring type burners disperse the flame more and are quieter, but are there
any taste/color differences produced in the final product?  It seems
logical you might get more caramelization and increased Maillard rxns. from
the focused flame type burner.  

I'm wondering if specific burners might be matched to produce a given beer
style.  For example, perhaps the focused jet engine type burner might be
favored for production of scotch ales such as a Traquair House clone. Any
thoughts?


Rick Foote
Whistle Pig Brewing Co.
Murrayville, GA






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Date: Mon, 21 Feb 2000 10:49:40 -0800
From: Charley Burns <cburns99 at pacbell.net>
Subject: re: Fire VS steam for the decoction heat source

lliB rehcaM asks in HBD #3254: Fire VS steam for the decoction heat source.
Any practical difference?

Heat is heat, but how _much_ heat is the key. Its been a while since I did
this research and couldn't even tell you where I read this (probably one of
S.A.'s posts here or maybe Noonan's last book) but -> the reason that
decoction's affect flavor is the creation of melanoidins. Melanoidins are
created in a liquid at high heat full of proteins and other enzymes. High
heat (from my memory) was defined as 225F and above.

I have found that it takes a minimum of 15 minutes of boiling a decoction to
get to the point where the aromas start smelling like baking bread. I
normally boil for an additional 5 minutes. Sometimes I have to add liquid
during the boil due to boiling down to near dry grains. To avoid liquor loss,
I tend to boil covered for 2 minutes, stir for a minute and then cover for 2.

lliB's qualification on the steam question was that he could only get it up
to 220F. It might work, but if you could get it warmer and keep it that way,
it would probably be possible and might actually be better (lower loss of
liquid).

yelrahC snruB in skaO riaF AC



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Date: Mon, 21 Feb 2000 14:01:50 EST
From: JDPils at aol.com
Subject: DME for yeast starters

Several months ago there was a posting about poor yeast starters with 
Lagglander extract.  I have had this experience as well.  Since then I have 
been using Munton and Fison DME and NEVER have a problem.   I always get a 
good foam kreusen and some trub stuck on the sides of the starter container.  
Recently I bought some extract from a different homebrew shop, since the one 
I went to for seven years(Evergreen Brewing Supply) burnt down.  All of a 
sudden I stopped seening any kreusen or trub stuck on the side.  I have made 
several starters including one with 1qt of slurry from a brewpub and while 
there is CO2 coming out they didn't look very active.

This prompted me to call the brew shop and find out that their bulk DME is 
eithr and American supply or Dutch other than Lagglander.  Needless to say I 
am a bit dumbfounded.  How can anyone brew a batch of beer with this stuff?  
Why is it the same yeast in the same volume of wort from a batch of beer 
shows proper fermentation?  I think the HBD should collaborate and get a list 
of these inferior DME's  and the better ones that work for starters.

I can also say, I will only recommend M & F for DME for ANY use until I can 
try other brands.

Cheers,

Jim Dunlap  


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---